Title: Keynes
1Keynes Beauty Contest Speculative Price
Bubbles in the Absence of Common Knowledge in
Experimental Stock Markets
- Shinichi Hirota and Shyam Sunder
- University of Iowa Workshop, Dec 7, 2001
2Valuation of Securities
- Value net present value of future cash flows
- Future is uncertain, value depends on investor
beliefs about the future cash flows - How far into the future?
- From now to liquidation of the the security
- From now to investment horizon (sale)
- Sale price depends on beliefs of other investors
about the cash flows after the sale - Return to formalization later
3Simple Example
- Investor A believes the net present value of cash
flows from now on to be 100 (fundamental value) - Investor should buy below 100 and sell above
- What if A also believes that tomorrow, others
will believe the net present value to be 150 - Considering second order beliefs, it may not
necessarily be best for A to sell at 110. A may
be better off buying at that price, with the
expectation of being able to sell at a higher
price - What is the best thing to do for an investor
whose first and second order beliefs are not
identical?
4Stories of Common Knowledge Assumption
- In a great deal of business modeling, common
knowledge is routinely assumed - What happens when it breaks down?
5Emperor Has No Clothes
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7Emperors Clothes
- The scoundrels made people believe that the
clothes will be invisible only to the incompetent
and the stupid - People thought that others believed it
- Nobody wants to be seen as stupid or incompetent
by others, lose his/her job - Visibility of clothes was private, it was easy to
fake seeing the clothes
8Emperors Clothes (Contd.)
- Scenario 1 Everyone was privately convinced of
their incompetence, and cheered to deny it
publicly - Scenario 2 People did not believe they were
incompetent just because they could see the naked
emperor, but believed that others so believed,
and cheered to avoid being seen as stupid
9What about the Child?
- The child did not know the link between
visibility and competence - Child was innocent, and said what he saw
- People know children to be innocent
- People knew that people knew this
10Stock Market
- Stock Market is like a newspaper beauty contest
- John Maynard Keynes, (1936)
11Newspaper Beauty Contest
Which Face is the prettiest?
12Which face will they judge to be the prettiest?
13Which face will they judge to be the prettiest?
14LIFO Inventory Accounting
- If your inventory prices rise, and end-of-year
inventory volume is stable or rising - You can delay paying taxes (higher net present
value of cash flows) - But have to report lower income also
- Many firms dont adopt LIFO
- Apprehension about stock market reaction (no
empirical support)
15Agency Problem
- Agency problem how to induce managers to
maximize shareholder value (e.g., choose LIFO) - Solution Link managerial compensation to
shareholder value - Problem 2 Value manipulation
- Solution Use market, not accounting, measures of
value
16Value Maximizing Manager in an Efficient Market
- LIFO can increase NPV of cash flow
- But manager maximizes stock price
- What does manager believe about how stock prices
are determined? - Suppose manager believes that stock prices depend
on income, not cash - Then manager is rationally led to reject LIFO
even if it saves cash for the firm
17Beliefs About Others Beliefs
- Common elements to the three stories about the
emperors clothes, stock market and LIFO - Central role of what we believe about others, and
about their beliefs
18Closing the Gap in Beliefs
- Is it possible for our first and higher order
beliefs to differ? - When they do differ, what does it take to get
them to converge? Aumann (1976). - Do they actually converge? Why or why not?
- When the beliefs of all around you are wrong,
does it pay to hold on to the right beliefs?
Fight them or join them? - Prior experimental results
- What are the consequences for theories of bubbles?
19Bubbles in Economic History
- Self-evident bubbles Galbraith, Kindleberger
- Econometric studies of long term recorded data
stock prices move sufficiently closely with
dividend over the long run to reject bubbles - Contemporary investors knew more than what the
econometricians have in their data - What changes in fundamentals can justify the 90
percent price drop during the Great Crash?
20Beliefs and Observation
- Theories of valuation are a function of beliefs
- In the field it is difficult enough to know the
first order investor beliefs, and their diversity - Second and higher order beliefs are practically
out of reach - In lab we might have a better, though still
limited, chance to know beliefs, perhaps even
open a gap between the first and higher order
beliefs and observe their consequences under
controlled conditions
21Models of Bubbles
- Tirole (1082, 1985) bubbles grow at discount
rate, no prediction about levels - First order beliefs Dti ? Dtij (second order
beliefs) - Investor need not be irrational in decisions or
beliefs, and need not believe the others to be
irrational. - Aumann common knowledge priors imply common
knowledge posteriors
22Professional Security Analysis
- Multi-billion dollar information intermediary
industry in U.S. alone - Typical report has current market price compared
to what the analyst predicts the future price to
be, and what the analyst believes the firm to be
worth - If investor beliefs were common knowledge, there
will be no rationale for such beliefs - Bubbles generated by gap between the first and
second order beliefs do not depend on investor
heterogeneity
23Finite Maturity Securities
24Finite Maturity Securities
- Cells C and D (sessions 3 and 4)
- All dividends except terminal dividends are zero
- Equilibrium price is constant through the 15
sessions - By design, second order beliefs have the chance
of being higher than the first order beliefs - Expect to observe bubbles as late as period T-1
in Cell C - Expect the bubble to crash in the last period
(Figure B)
25Indefinite Maturity Securities
26Indefinite Maturity Securities
- Cells A and B
- All dividend except liquidation dividend are zero
- Session does, and is expected to end before
liquidation - Terminal payoff by endogenous prediction game
(see Figure A for price path)
27Experimental Design
- Double auction market for multiple units of a
single security that pays single liquidating
dividend - Multiple trading periods (3 minutes each)
- Each investor endowed with 10 shares, 10,000
points in cash - Liquidation by dividend or predicted price
- Predictors knew the rules, no endowments, no
ability to trade, could watch trading, knew the
range of terminal dividends
28Experimental Design
29Experimental Parameters
30Trading Screen
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32Cell A (Session 1)
- Endogenous, gap
- Small bubble (10 percent)
- Highly stable
- No crash
- High correspondence between actual and predicted
prices - Efficient security transfer late but not early
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34Cell B (Session 2)
- Endogenous, no gap
- Huge bubble, well above second order belief
limits - Highly stable
- Did not crash
- Allocations suggest that terminal dividends
ceased to play any important role in driving
trading, largely driven by prediction
35Tentative Conjectures
- Conjecture 1 In absence of exogenously specified
terminal dividend, price bubbles can form, and
persist through the end of a session.
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37Cell C (Session 3)
- Exegenous termination, gap
- Large bubble, prices above upper limit of second
order beliefs - Bubble burst earlier than last period
- Error by one trader (forgot terminal dividend)
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39Cell D (session 4)
- Exogenous termination, no gap
- No bubble
- Fundamental price and allocations
40Tentative Conjectures
- Conjecture 2 Even with exogenous terminal
dividend and known horizon, bubbles can form when
there is a gap between first and second order
beliefs. - Conjecture 3 In the presence of exogenously
specified terminal dividend, end-of-the-session
prices converge to the equilibrium level
determined by such dividends.
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42Results A Gap, Endogenous Termination
43Discussion
- Shiller prices too volatile
- French and Roll Market trading itself creates
volatility (possibly through formation of second
order beliefs?) - Significant part of market returns realized as
capital gains, not dividends - Valuation models should incorporate second order
beliefs
44Discussion
- Stock prices can stabilize far from fundamental
price levels - Price predictions can simply reinforce deviations
from fundamentals - In a market dominated by capital gains traders,
price can be decoupled from fundamentals - Consistent with gap between first and higher
order beliefs generating price bubbles
45Bubbles and Rationality
- Lei, Noussair and Plott observe bubbles in
absence of speculative trading - Lack of understanding by subjects of the market
structure, task, opportunities - Lack of correspondence between the intended and
subjective experimental environment - Difficult to determine the correspondence
- Is lack of understanding irrational?
- Need get inside irrationality.
46Candidates to be Examines
- Gap between intended and subjective experimental
environment - We tried this in a fifth session observed many
errors in spite of better instructions - Link between uncertainty and bubbles
- Link between low dividend securities (larger
duration) and bubbles
47Thank You
- The paper will be available on
- http//www.som.yale.edu/faculty/sunder/research
- My email is shyam.sunder_at_yale.edu
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51Financial Analysis, Trading Volume and Bubbles
- Mostly fundamental analysis, assumes common
knowledge - Assumption relaxed by convenience
- Models of price bubbles based on relaxing the
common knowledge assumption - Trading volume models based on diverse beliefs
52Models of Weakening Common Knowledge Assumption
- Efficient markets may fail to discipline managers
(Amershi and Sunder) - Alternatives to fundamental valuation model, even
technical models - Models of corporate disclosure (unraveling does
not work in practice) - Understanding results of ultimatum games
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54Levels of Analysis
55Thank You
- The paper, and slides will be available next week
at - http//www.som.yale.edu/faculty/sunder/research.ht
ml - or email to shyam.sunder_at_yale.edu
56The purpose of our study
- Explore why the price bubble occurs in stock
markets - Investors belief on others belief
- Stock market experiments
57Stock market bubble in the real world
- Internet Bubble
- e.g. Yahoo
- 10 now, 250 in the peak
- Japan late 80s
- e.g. Nikkei 225 Average
- 10,000 yen now, 40, 000 yen in the
peak - Must be bubbles
- Why bubbles occur
58Investor should expect ...
- Infinitely lived investor
- Discounted value of future dividends
- Finite horizon investor
- Resale price
- Others valuation
- Others expectation for the future
- Future dividends
- Future price
-
59If he believes that
- Others will believe high future dividends or high
future price, - What should he do?
- Even if he does not believe high future dividends
or high future price.
60If every investor believes that
- Others will believe high future dividends or high
future price, - What will happen?
- Even if every investor himself does not believe
high future dividends or high future price
61Stock prices
- are determined by
- not investors own beliefs
(first-order-beliefs) - but investors beliefs on others beliefs
(second-order-beliefs) - Any Price can be observed depending on
second-order-beliefs
62Bubbles
- Price ? Fundamental Value
- Price
- Second-order-belief
- Fundamental Value
- First-order-belief
- Second-order-belief ? First-order-belief
63Keynes
- Newspaper beauty contests
- Well-known and popular story
- True in real world?
- How to verify?
- Fundamental value is unobservable
- Gap is unobservable
64Experimental Study
- Laboratory
- Fundamental value is observable
- Create the gap between FOB and SOB
- See the effect of the gap on the stock price
- Experimental Results
- Bubbles occurred due to the gap
- Keynes is right!
65Experimental Markets
- Stock market in the laboratory
- Trade a single stock
- 15 (12) periods of 3 minutes each
- Stocks has a life during the experiment
66How to create the gap between FOB and SOB
- Each investor knows dividends (FOB)
- But SOB may be different from FOB
- Market 1
- Dividends may not be received in the investment
life. - Dividends are paid only if the session lasts for
30 periods - The subjects can easily guess that the session
ends earlier - The stock at the last period is evaluated at the
predicted price of the next period - They have to expect what the market expects the
price -
67How to create the gap between FOB and
SOB(continued)
- Market 2
- 15 periods. Dividends are paid at the end of
Period 15. - Each knows his dividend, but does not know
others dividends - Investors draws the dividend card
- Private information
- The dividend range is informed to everyone
- Investors have to guess others dividends, i.e.,
others valuation of the stock.
68Investrors and Predictors
- Investors
- 10 stocks, 10,000 cash
- trade stocks using caplabTM system
- receive money depending on profits
- Predictors
- predict the next periods price
- receive money depending on the accuracy
69Conducted Experimentswhat, who, where, when
- 2 sessions for Market 1 (Session 1, 2)
- 1 session for Market 2 (Session 3)
- Yale university, undergraduate students
- Yale School of Management, B-74 Room
- September 21, 29, 30, 2001
70Conclusion (from preliminary experimental
results)
- The investors beliefs on others belief (SOB)
significantly affect the stock prices. - The gap between FOB and SOB seems to create
bubbles in stock markets.